x86,um: switch to generic old sigsuspend()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
index 53c90fd..a372582 100644
--- a/arch/x86/um/Kconfig
+++ b/arch/x86/um/Kconfig
@@ -25,6 +25,7 @@
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select MODULES_USE_ELF_REL
 	select CLONE_BACKWARDS
+	select OLD_SIGSUSPEND3
 
 config X86_64
 	def_bool 64BIT